The Samsung Galaxy S6 (SM-G920) & Samsung Galaxy S6 Edge (SM-G925T) cell phone from T-Mobile USA are both using a custom firmware preventing the phone from being unlocked by code as there is no way to enter it (these phone are simply not asking for “SIM Network Unlock PIN”). Before this post, the only way to Unlock the phone was by using the official T-Mobile  “Mobile Device Unlock App” which is an Android app called “Device Unlock” that allows you to request and apply a mobile device unlock directly from the device.

Original “Locked Screen” of a Samsung Galaxy S6 from T-Mobile USA

So what do you do if you get an Unlock Code but you cannot use it?

Now there is a solution consisting of an upgrade to the firmware of the phone with MetroPCS Firmware instead of T-Mobile, and this will allow the phone to ask for the Unlock Code. Below you will find a tutorial about how to do this. Once you flash (update) your Phone with this New Firmware, please make sure that your Samsung SM-G920T or SM-G925T is now asking for “SIM Network Unlock PIN”.

Service Name: Samsung T-Mobile USA [NEW GEN 2015] – NCK + SPCK (1<>4 Hours Mon-Fri) – [Tool ID: 775]

Step by Step Tutorial Firmware Upgrade
Samsung Galaxy S6 (SM-G920T) & Galaxy S6 Edge (SM-G925T) to MetroPCS Firmware

Disclaimer: GSMUnlockUSA is not responsible if users break / brick or damage their phone while trying to use this method. You must not use this firmware for any other Android Cell Phone other than the Samsung Galaxy S6 (SM-G920T) or Samsung Galaxy S6 Edge (SM-G925T) from T-Mobile USA. Do so at your own risk. If you’re not sure what you are doing, please seek assistance at a local cell phone service center in your area.

Step 1 (Preparation): 

1. Galaxy S6:  Download the Special MetroPCS Firmware for Samsung SM-G920T.
2. Galaxy S6 Edge: Not Available yet (working on it) so please check later….
3. Download ODIN v3.10.0 Service Software using this link (NEW: Odin v3.10.5 or Odin v3.10.6)
4. Make sure your phone battery is charged more than 60%.
5. Enable USB Debugging, by open Settings > Developers Option > USB Debugging
   If Developers Option is hidden, go to Settings > About Phone > Built Number (tap on it for 5-8 times)
6. Make sure you install the Samsung Galaxy S6 / S6 Edge USB drivers on your PC, if you haven’t already.

Optional (Galaxy S6) : Download the Original T-Mobile Firmware for Samsung SM-G920T.
Optional (Galaxy S6 Edge) : Download the Original T-Mobile Firmware for Samsung SM-G925T.

Step 2 (Update Firmware): 

1. Run Odin3 v3.10.0 as administrator (Right-Click: Run as Administrator).
2. Switch OFF your Samsung Galaxy S6 / S6 Edge
3. Boot in download mode, by pressing the Volume Down + Home + Power Key simultaneously.
   
4. When you see the screen below:
   

   Samsung Galaxy S6 Edge in Download Mode

   Tap Volume Up button to enter Download Mode.

5. Connect the Samsung Galaxy S6 to your PC with the USB cable.
   Odin will automatically detect your phone and show the “Added!” message.
6. In the Odin, click on AP or PDA and then choose :- For Galaxy S6 (SM-G920T) :G920T1UVU1AOCH_G920T1TMB1AOCH_TMB_HOME.tar.md5 file.
   – For Galaxy S6 Edge (SM-G925T): Not Available yet (working on it) so please check later….
7. Ensure Auto Reboot and F. Reset Time options are selected selected in Odin
   while the Re-Partition option is unchecked (this is very important).
8. Click Start in Odin and wait for the software to update your phone.
9. Once the root installation is done, your phone will reboot
   and soon a PASS message with a green background appears in the left-most box at the very top of Odin.
10. You can close Odin after device turns on.
11. Your Samsung Galaxy S6  / S6 Edge is now fully updated with MetroPCS Firmware!

AFTER FLASHING A SAMSUNG GALAXY S6 / S6 EDGE FROM T-MOBILE WITH THIS FIRMWARE THE PHONE WILL FINALLY ASK FOR A NETWORK CODE WHEN YOU PUT A NON APPROVED CARRIER’S SIM CARD ON THE PHONE.

AFTER YOU HAVE UNLOCKED YOUR PHONE YOU CAN STILL FLASH A T-MOBILE FIRMWARE BACK TO THE DEVICE SO THAT IT GOES BACK TO ORIGINAL STOCK AND SO DOES NOT LOSE WARRANTY. BUT THE PHONE WILL RELOCK AS SOON AS YOU FLASH IT BACK WITH T-MOBILE FIRMWARE.

• Download the Original T-Mobile Stock Firmware for Samsung SM-G920T (Galaxy S6).
• Download the Original T-Mobile Stock Firmware for Samsung SM-G925T (Galaxy S6 Edge).